Mysql - take a look at server and install TOra or other tool

I have a dedicated centOS server runing mysql for my small CRM system but mysql seems to be overloading the server. I use a very simple CRM system and a radius server to manager some hotspots.. I thinkt that the queries a freelancer coder developed may have few issues (mostly the php are at one domain and tables at other, same server, and i also dont know if this creates delays). I need someone to take a look, install a free open source analysis too and give me some advice.